RIALTO - An autopsy to determine Rodney King's cause of death was performed Monday but how and why he died could remain a mystery for several weeks.

King, 47, who became famous after he was severely beaten by Los Angeles police in 1991, was found at the bottom of his pool Sunday morning in Rialto.

San Bernardino County sheriff's officials released few details Monday following the examination by the county's coroner.

"They will be doing toxicological tests, which will take weeks to get back," said Sheriff's Department spokeswoman Jodi Miller.

Such tests are needed to determine if chemicals - such as drugs or alcohol - were present at the time of death.

No final ruling on the cause and manner of death will be made until the requested test results have been received and reviewed with the autopsy findings, according to the Sheriff's Department.

Rodney King was found dead Monday at the bottom of his swimming pool in his Rialto home. (Associated Press)

That could take as long as four to six weeks.

King's fiancee called police at 5:25 a.m. Sunday after she found him at the bottom of his backyard pool in the 1000 block of East Jackson Street in Rialto. She told police she wasn't an avid swimmer like King, but she did try without success to rescue him.

Rialto police Capt. Randy De Anda said King was submerged three to four minutes between the time his fiancee called 911 and when officers arrived and pulled him from the water.

Paramedics took him to Arrowhead Regional Medical Center in Colton, where he was pronounced dead at 6:11 a.m.

De Anda said he saw no alcohol containers or drugs by the pool and there were no obvious signs of foul play or trauma.

"Right now, we're obviously investigating it as a drowning," De Anda said. "We want to make sure it's a thorough investigation."

King was 25-years-old and on parole from a robbery conviction in 1991 when Los Angeles police stopped his vehicle because he was speeding. He had been drinking and later said it led him to try to evade police.

Four white Los Angeles police officers hit him more than 50 times with their batons, kicked him and shot him with stun guns.

The 1992 Los Angeles riots, which were set off by the acquittals of the officers who beat King, lasted three days and left 55 people dead, more than 2,000 injured and swaths of Los Angeles on fire. At the height of the violence, King pleaded on television: "Can we all get along?"

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